03.01.13 9:45 AM ET

In the introduction to her new book, Lean In: Women, Work, and the Will to Lead, Facebook COO Sheryl Sandberg says that she’d been cautioned against speaking out on the dearth of female leadership in this country, and anticipates that some will dismiss what she has to say because of her immense wealth. “My hope is that my message will be judged on its merits,” she writes. She may have been hoping for too much. Lean In, which Sandberg describes as “sort of a feminist manifesto” about the need for more women in powerful positions, doesn’t come out for another 10 days, but a strange, sour backlash has already begun, aimed less at what the book says than at who Sandberg is.

Writing in USA Today, Joanne Bamberger, who either didn’t read Lean In or didn’t comprehend it, lumps Sandberg in with Yahoo CEO Marissa Mayer, accusing both of launching “the latest salvo in the war on moms.” In The New York Times, the usually supercilious Maureen Dowd evinced a sudden concern for feminist authenticity, slamming Sandberg for co-opting “the vocabulary and romance of a social movement not to sell a cause, but herself.”

Melissa Gira Grant, writing in The Washington Post, carps that “this is simply the elite leading the slightly-less-elite, for the sake of Sandberg’s bottom line,” which makes sense if you believe that a woman worth hundreds of millions of dollars would go into feminist publishing for the money. (Skirting feminist self-parody, Grant proceeds to complain that Sandberg fails to grapple with the struggles of domestic workers, the unemployed, people whose caretaking duties extend beyond children to aging parents as well as “close friends and extended families,” women who can’t have children, and those who are lesbian, bisexual, or transgender.) Weighing in at Forbes.com, Deanna Zandt admits that she didn’t bother trying to get a review copy of Lean In, but nonetheless claims that Sandberg’s message is “buck up, little campers. It’s a tough world, and you’ve got to be tough.”

These attacks, largely divorced from anything Sandberg has actually written or said, mean that there’s already a lot of public misunderstanding of her book’s message. One would think she was peddling a multilevel marketing scheme, not the most overtly feminist mainstream business book ever written. True, she wants to work within the system rather than smashing it, and parts of her book, as she acknowledges, “will be most relevant to women fortunate enough to have choices about how much and when and where to work.” But so what? No book speaks to everyone, and leadership tomes by wildly successful male executives aren’t typically pilloried for ignoring the concerns of immigrant day laborers.

Lumping Sandberg with Marissa Mayer is particularly unfair. Mayer has said that she doesn’t consider herself a feminist, because she doesn’t have the “militant drive and sort of the chip on the shoulder.” Sandberg constantly quotes Gloria Steinem and writes that she regrets her reluctance to embrace the feminist mantle earlier in life. Mayer abolished working from home at Yahoo. Sandberg calls for “[g]overnmental and company policies such as paid personal time off, affordable high-quality child care, and flexible work practices.” She has achieved nearly inconceivable levels of wealth and power, and she wants to use it to pull other women up as well. Isn’t that what feminists have always wanted from women who’ve had great success?

In a formulation Sandberg uses again and again, she writes, “A truly equal world would be one where women ran half our countries and companies and men ran half our homes. I believe that this would be a better world.” We are, of course, quite far from such a world. Sandberg repeats the dismally familiar figures: “Women hold about 14 percent of executive officer positions, 16 percent of board seats, and constitute just 18 percent of our elected congressional officials.” She points out that, in a 2007 survey of Harvard Business School alumni, only 49 percent of women who graduated in the early 1990s were working full-time. “This exodus of highly educated women is a major contributor to the leadership gap,” she writes.

Now, some might say that we shouldn’t waste our time worrying about the fate of Harvard Business School alumna and other high-class women. That means, however, accepting that all our important institutions will continue to be run by men. Anyone who doesn’t want that should take Sandberg seriously.

So why aren’t more women reaching the top of their professions? In her book Sandberg identifies internal and external obstacles holding women back. Outright discrimination, as well as more subtle structural barriers, means there are fewer women at the top. The existence of a mostly male power structure, in turn, makes it hard for women to imagine themselves as leaders, which saps their confidence and ambition.

Sandberg acknowledges that both sets of obstacles need to be taken on, but she’s chosen to focus on the internal obstacles because they are under women’s own control. “We can dismantle the hurdles in ourselves today,” she writes. Her book is largely about how to do that within the context of a sexist society. It’s written with an understanding that the deck is stacked against women, and the hope that if more women become more powerful they might be able to change that.

Lean In isn’t perfect. Parts of Sandberg’s plan to create a movement around it based on small group “Lean In Circles” will be off-putting to anyone who dislikes corporate culture. I groaned when I read, in The New York Times, that she’s asked participating women to share only stories with positive endings, “suggesting that tales closing with missed promotions or broken marriages are unwelcome.” Her insistence on mandatory monthly meetings—participants can miss no more than two a year—is misguided, especially given how starved her target audience is for time.

But this doesn’t explain the anger directed toward her—after all, she’s still doing more than most women in corporate American to advance the cause of gender equality. Instead, I think the reaction to Sandberg stems from something that she herself identifies. Women are conditioned to compare themselves with one another. When we’re not wholly at peace with our own choices—and who is?—those comparisons sting. “There is always an opportunity cost, and I don’t know any woman who feels comfortable with all her decisions,” Sandberg writes. “As a result, we inadvertently hold that discomfort against those who remind us of the path not taken. Guilt and insecurity make us second-guess ourselves and, in turn, resent one another.”

This seems like a pretty good explanation for some of the more unhinged reactions to her book. Bamberger’s claim about a “war on moms” is particularly off given how much attention Sandberg pays to the needs of working mothers, and how frequently she expresses respect for those who take care of kids full-time. At one point, she writes, “Full-time mothers can make me feel guilty and, at times, intimidate me … But when I push past my own feelings of guilt and insecurity, I feel grateful. Full-time parents—mostly mothers—constitute a large amount of the talent that helps sustain our schools, nonprofits, and communities.”

Yet if someone who lacks Sandberg’s ambition wants reassurance about leaning back rather than advice about moving ever upward, such magnanimous words may not register. Instead, her exhortations could feel like an insult. That’s unfortunate, but it’s not the fault of the book. Her message isn’t that all women need to be corporate executives or high-powered lawyers or political leaders. It’s that we’d be better off if more corporate executives, high-powered lawyers, and political leaders were women. Argue with that premise if you want, but don’t pretend that Sandberg isn’t doing all she can to make it happen.